There is known in the prior art, seen in FIG. 1, a time base formed for example by a piezoelectric resonator, such as a quartz resonator 1, or a silicon MEMS resonator connected to the terminals of an oscillator 2 whose output is connected to a frequency divider circuit 3 to obtain the required operating frequency for the watch to indicate the exact time. The output of frequency divider circuit 3 is connected to a control circuit 4 of an electric motor 5, for driving the gear trains, not shown here, rotating the analogue display means, such as hands used to provide the time indication, i.e. the hours, minutes and possibly seconds. The resonator, the oscillator, the divider circuit and the control circuit are placed in the same case 6.
However, it is not possible with this configuration to have a circuit that is independent of fluctuations in temperature, since no temperature compensation circuit is provided.
There are known thermally compensated timepiece circuits. These circuits include a timepiece module connected to a quartz and also connected to a temperature measuring and correction circuit. This measuring and correction circuit is thus arranged for measuring the temperature and correcting the operation of the clock circuit.
One drawback of these circuits is that they occupy space, i.e. they have a large surface area, and calibration is carried out on the assembled calibres. This increases the manufacturing cost of the temperature dependence correction performed on the calibres. Moreover, this configuration is sensitive to any moisture that infiltrates the timepiece case. This moisture sensitivity leads to a deterioration in the accuracy and reliability of the clock circuit.
Further, for a clock circuit having a chronograph function, there is the added drawback of having an additional module and thus the same problems of surface area and moisture sensitivity.